Republican lawmakers who voted Thursday for a bill to fund the remaining fiscal year 2019 appropriations bills said they wish to learn exactly how President Trump plans to declare a national emergency to find additional funds for the border wall before making a judgment.

The Senate passed H.J. Res. 31, the fourth and final FY ’19 appropriations package that included funding for the Department of Homeland Security, by an overwhelming majority of 83-16 Thursday afternoon. The House is expected to take up the bill later this evening and speedily approve it.

As part of infrastructure reinforcement under Operation Secure Line, members of the U.S. Army 104th Engineer Construction Company, 62nd Engineer Battalion, 36th Engineer Brigade install concertina wire on the border wall east of the Port of Nogales, AZ, Deconcini Crossing, on November 28, 2018. (Photo: Customs and Border Patrol)

Senate Majority Leader Mitch McConnell (R-Ky.) took to the floor ahead of the vote to announce that Trump indicated to him that he would sign the compromise bill to avoid a second government shutdown, but then move to declare a national emergency to make up the remaining funds he desires to build new barriers along the U.S. southern border.

The compromise bill provides $22.54 billion for border security, including $1.375 billion for 55 new miles of physical barriers along the border. Trump has previously called for up to $5.7 billion in funds for new barrier construction.

While Democratic lawmakers have long resoundingly criticized the tactic, Republican senators were hesitant to judge either way before learning more about how Trump would invoke the national emergency.

“I just don’t know what he will actually cite as the statutory authority that he might wish to carry out,” said Sen. Mitt Romney (R-Utah), a member of the Senate Homeland Security and Government Affairs Committee. “We’ll wait and see what he does and then respond to that based upon the legal theory, the statutory authority that he selects.”

Sen. Rand Paul (R-Ky.), a fellow member of the Senate Homeland Security Committee who voted no on the compromise bill, noted that he does not usually endorse spending funds outside of congressional appropriations.

“But that being said, there are rules that allow some money to be moved around,” he told reporters. “I don’t know what authority he is citing or what he has done so far. I think we have to kind of wait until he announces what he’s actually for.”

Sen. Rob Portman (R-Ohio), another Senate Homeland Security Committee member, said he will have to take a look at the specific declaration before making a decision. “I’m just really glad the president is signing this bill, because I think the shutdown would have been a disaster,” he said.

Republican Policy Committee Chairman Roy Blunt (R-Mo.) said he would be supportive of certain ways that Trump might transfer funds, “and there are other ways I’d have a lot of problems.”

“I’m glad he’s signing the bill and I also appreciate the fact that it doesn’t give him as many tools as he should have to secure the border,” he added.

Senate Armed Services Committee (SASC) Chair Jim Inhofe (R-Okla.) told reporters Feb. 12 that he would not support the president taking funds out of the Pentagon’s military construction fund to build more barriers, but he could reluctantly endorse the idea of using the Army Corps of Engineers’ budget – typically used for civil engineering efforts – instead.

He noted that those were “two bad choices,” but “if it happens to be that way, leave military construction alone.” Inhofe also voted no on the compromise bill Thursday.

There contains about $21 billion in unobligated DD military construction funds that Trump could potentially target for border wall construction, according to congressional aides.

Those military construction and family housing appropriations are  detailed on a project-by-project and location basis, notes Byron Callon of the Capital Alpha Partners in a Thursday email to investors. “Funds are not just for barracks but can include air base modifications for bed-down of new aircraft, such as the F-35,” he said. “They are an essential element of military readiness and recruitment and retention of military and civilian personnel.”

Rick Berger, a research fellow at the Washington, D.C.-based American Enterprise Institute and a former Senate Budget Committee staffer, noted on Twitter Thursday evening that “unobligated” does not mean the funds are “unused.”

“It just means a contract hasn’t been signed yet, which takes a long time for construction — up to a decade,” he added. “All this money–tens of billions of dollars–is explicitly authorized/provided by Congress for specific projects.”

Sen. Richard Shelby (R-Ala.), Senate Appropriations Committee Chair and one of the key negotiators for the compromise bill, said he would “probably” support Trump’s declaration of a national emergency. “He’s got constitutional powers to do all that, it has nothing to do with us,” he added.

Several Republican senators, including Sens. Susan Collins (Maine) and Lisa Murkowski (Alaska), said they did not support the potential of a national emergency. Murkowski told reporters she did not view the situation as “a matter that should be declared a national emergency.”

Collins said in a statement: “I don’t believe that the National Emergencies Act contemplates a President unilaterally reallocating billions of dollars, already designated for specific purposes, outside of the normal appropriations process. … A far better approach would be for the President to submit a timely budget request for additional border security funding and work with Congress through the normal appropriations process.”

The House did not pass the compromise bill by Defense Daily’s deadline Thursday, but is largely expected to do so.

House Speaker Nancy Pelosi (D-Calif.) said she may file a legal challenge should Trump declare a national emergency during her weekly press conference Thursday.

She added that she does not expect the development to affect how the House votes on the spending bill.

Pelosi noted that Republicans should be concerned about the precedent such a declaration would set for the future.

“Just think of what a president with different values can present to the American people,” she said. “Democratic presidents can declare emergencies as well. So the precedent that the president is setting here is something that should be met with great unease and dismay by the Republicans and of course we will respond accordingly when we review our options. First we have to see what the president actually says.”